Abstract

The formation of patterns in models of degenerate optical parametric oscillators (DO-POs) has been studied mainly for negative detunings [1]. Robust soliton-like stripes have however been predicted in the signal field of the same model for zero or positive detunings [2]. Such stripes correspond to diffractive domain walls separating signal fields of opposite (homogeneous) phases. They are stable in one transverse dimension but need special boundary conditions (such as Neumann conditions on a square grid [2]) to stabilise in two dimensions. In fact, under normal conditions of operation for DOPOs in two-transverse dimensions, domain walls disappear after fast transients for zero or positive detunings, as shown in the first three panels of the Figure.

© 1998 IEEE